The utilization of a filter means to separate solids from liquids is, of course, well known. It has also been proposed to automatically filter such solid-liquid mixtures. However, there has heretofore not been provided a satisfactory device which will both aliquot and filter. Often the liquid filtrate obtained from the liquid-solids prefiltration mix is subject to further testing and/or analytical procedures for chemical or medical purposes. While automatic filtration apparatus would be very helpful in procedures of this type, particularly when substantial numbers of filtrate samples are necessary, it has heretofore been generally necessary to conduct such filtration by manual procedures.
Such manual procedures have been considered necessary because of the degree of accuracy required -- which is not always available with automatic filtering apparatus -- and to reduce the possibility of introducing an impurity into the filtrate. Manual procedures for obtaining aliquot filtrates, as is well known, involve the use of filter paper, funnels, pipets and collecting tubes, all handled by technicians or scientists. Such manual procedures are time-consuming and slow, cumbersome and expensive.